• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.74.2-74.2
• /
• 2013

Recent spectroscopic observations have provided evidences for the multiple stellar populations having different abundances in some massive globular clusters (GCs). In particular, some of these GCs show clear separations of red giant-branches (RGBs) in calcium narrow band photometry. In order to confirm the differences in heavy element abundances and radial velocities among multiple RGBs, we have performed the low-resolution spectroscopy for the RGB stars in these GCs. The spectral data were taken from the multi-object spectroscopic mode with WFCCD mounted on the du Pont 2.5m telescope in Las Campanas Observatory. In this talk, we will present our progress in the spectroscopic analysis of the RGB stars in these GCs.

• Journal of Astronomy and Space Sciences
• /
• v.27 no.4
• /
• pp.309-318
• /
• 2010

We introduce a technical approach for reducing three-dimensional infrared (IR) spectroscopic data generated by integral field spectroscopy or slit-scanning observations. The first part of data reduction using IRAF presents a guideline for processing spectral images from long-slit IR spectroscopy. Multichannel image reconstruction, Image Analysis and Display (MIRIAD) is used in the later part to construct and analyze the data cubes which contain spatial and kinematic information of the objects. This technic has been applied to a sample data set of diffuse 2.1218 ${\mu}m$ $H_2$ 1-0 S(1) emission features observed by slit-scanning around Sgr A East in the Galactic center. Details of image processing for the high-dispersion infrared data are described to suggest a sequence of contamination cleaning and distortion correction. Practical solutions for handling data cubes are presented for survey observations with various configurations of slit positioning.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.1
• /
• pp.38.1-38.1
• /
• 2013

We present observational estimation of the infrared (IR) luminosity function (LF) of local (z < 0.3) star-forming (SF) galaxies derived from the AKARI NEP-Wide samples. We made an analysis of the NEP-Wide data with optical spectroscopic information allowing an accurate determination of luminosity function. Spectroscopic redshifts for about 1650 objects were obtained with MMT/Hectospec and WIYN/Hydra, and the median redshifts is about 0.22. To measure the contribution of SF galaxies to the luminosity function, we excluded AGN sample by comparing their SEDs with various model template. Spectroscopic redshifts and the AKARI's continuous filter coverage in the mid-IR (MIR) wavelength (2 ~ 25 micron) enable us to avoid large uncertainties from the mid-IR SED of galaxies and corresponding k-corrections. The 8-micron luminosity function shows a good agreement with the previous works in the bright-end, whereas it seems not easy to constrain the faint-end slope. The comparison with the results of the NEP-Deep data (Goto et al. 2010) suggests the luminosity evolution to the higher redshifts, which is consistent with the down-sizing evolutionary pattern of galaxies.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.6
• /
• pp.947-951
• /
• 2005

Rotating compensator multichannel spectroscopic ellipsometry has been employed to determine the optical functions of various liquids used in chemistry. We attempted three different measurement configurations: (1) air-liquid interface, (2) prism-liquid interface, and (3) liquid-sample interface. In prism-liquid interface, we found that the prism surface had roughness and it should be considered in analysis for accurate results. In liquidsample interface, we had much higher reflection, better sensitivity, and less limitation compared to the other two configurations when crystalline silicon was used as reference sample. We discuss the merit of each configuration and present the optical functions of various liquids. Also we demonstrate Bruggeman effective medium theory to determine the optical properties of mixed liquid.

• Natural Product Sciences
• /
• v.17 no.4
• /
• pp.350-353
• /
• 2011

A new daucosteryl derivative, verticilloside (1), was isolated from the seeds of Malva verticillata L. (Malvaceae). The structure was determined to be 3-O-[${\beta}$-D-(6'-linoleoyl)glucopyranosyl]-${\beta}$-sitosterol based on spectroscopic analyses ($^1H$ and $^{13}C$-NMR, DEPT, COSY, HMQC, and HMBC) and chemical reactions.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.65.1-65.1
• /
• 2017

We present the high-resolution spectroscopic study of the red-giant branch (RGB) stars in the peculiar globular cluster M22 (NGC 6656). We obtained high-resolution spectra of 55 RGB stars using the CTIO 4-m telescope and the HYDRA multi-object spectrograph. By employing an improved LTE analysis method, we measured accurate elemental abundances. In this talk, we will discuss the differences in the chemical composition between the two stellar populations in the context of the formation of M22.

• Korean Journal of Optics and Photonics
• /
• v.5 no.2
• /
• pp.231-237
• /
• 1994

We present spectroscopic methods to analyze the structural parameters of tandem Fabry-Perot interferometers. By using laser beams of two different frequencies by several tens of GHz, we investigated the cavity spacings of the two interferometers and ways to measure and to find the limitation of the neccesary conditions between the two interferometers. All of the theoretical results has been also confirmed experimentally.ntally.

• Natural Product Sciences
• /
• v.21 no.4
• /
• pp.273-277
• /
• 2015

Comprehensive chemical analysis of extracts and fractions of marine actinomycete strains led to the discovery of a new minor secondary metabolite, salternamide E (1), from a saltern-derived halophilic Streptomyces strain. The planar structure of salternamide E (1) was elucidated by a combinational analysis of spectroscopic data including NMR, MS, UV, and IR. The absolute configuration of salternamide E (1) was determined by circular dichroism spectroscopic analysis. Salternamide E displayed weak cytotoxicity against various human carcinoma cell lines.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.1380-1382
• /
• 2003

Detection of sea fog by remote sensing with spectroscopic analysis method and structural analysis method is introduced in this paper. On this base, designing principles and frame of weatherproof detection system of sea fog by remote sensing are systemically explained. Using GMS5 and NOAA visible and infrared channel data, progresses of sea fog on yellow sea on April 17,18, 2001 is monitored which accord with the observing.

• Korean Journal of Food Science and Technology
• /
• v.23 no.4
• /
• pp.447-451
• /
• 1991

Red pepper peels stored with seeds or stems in the powder state at $30^{\circ}C$ resulted in decrease of quality components such as capsanthin, capsaicin and total sugars. The effect of seeds on the quality deterioration was larger than stems. A near-infrared reflectance spectroscopic(NIRS) method was evaluated for the determination of seed and stem contents in red pepper peels. The standard error of prediction was 1.76% in seeds and 0.43% in stems. It is concluded that the NIRS method is suitable for the determination of seen and stem contents in red pepper powder.